There’s a strong body of opinion that rates Nebbiolo as Italy's greatest red grape, since it’s responsible for Barolo and Barbaresco, but the variety isn’t widely grown outside Piedmont due to finicky microclimatic requirements. Regardless of its place in the vinous pecking order it is one of the world's most distinctive grape varieties. In 2004, research found Nebbiolo to be related to Piedmontese Freisa and French Viognier. Despite the prestige and acclaim, Nebbiolo now accounts for less than 6% of Piedmont’s vineyards (5,100 ha in 2000), accounting for just over 3% of the region’s production.
Named for the Italian nebbia (fog), a reference to autumn mists, or to the fog-like bloom that forms over the berries as they ripen, or perhaps derived from the Italian nobile (noble), Nebbiolo is difficult to grow, needs an appropriate microclimate and is one of the first Piedmontese varieties to bud but the last to ripen, usually harvested in mid to late October. Producers often finish fermenting Barbera and Dolcetto before Nebbiolo is picked.
The earliest references to Nebbiolo in the Alba district, between Milan and Turin, date back to the thirteenth century though the variety may have been known to the Romans. The largest plantings are, predictably, in Piedmont, but it is also found in Argentina, Uruguay, Chile, California, Austria, Switzerland and Australia.
Nebbiolo has about forty different clones and producers often use a variety of clones to deliver greater complexity. Vines are vigorous and bear well, although climatic and soil conditions determine the quality, and the juice requires careful handling. Nebbiolo prefers soils with high clay and limestone content, tolerates some other soil types and produces wines that reflect the concentration of minerals, including manganese, magnesium and potassium. It is highly susceptible to coulure, particularly if it rains during budbreak or flowering, needs shelter from wind and dry weather, dislikes warm climates but needs to be grown on sunny south and southwestern facing slopes to develop sugars and fruit flavours to balance high acidity and robust tannins. Red grapes such as Barbera and white grapes (particularly Arneis) are often blended with Nebbiolo to add colour and soften the tannins.
The juice has high levels of acid, alcohol and tannin, resulting in lightly coloured highly tannic wines with a distinct brown colour. Nebbiolo is usually long lived, developing into rich wines with a characteristic brick-orange hue at the rim of the glass, fruity berry and floral perfumes and a complex full palate with spicy, chocolate, leathery and earthy, forest floor flavours which will continue to improve as the tannins come into balance with the other characters. As the wines age, the bouquet becomes more complex, revealing aromas and flavours including violets, tar, wild herbs, cherries, raspberries, truffles, tobacco, prunes and liquorice.
In Barolo, a division between traditional and modernist approaches to Nebbiolo stems from the era winemakers were unable to control temperatures during fermentation. Cool temperatures delay fermentation in late harvested grapes, resulting in lengthier maceration and increased extraction of tannins. Then, when fermentation started, temperatures within the must could reach 38 °C, reducing aromas and flavours and delivering wines that needed years in oak to soften the tannins.
Modern winemaking equipment allow producers to mix modern technique and traditional winemaking with lengthy maceration (20 to 30 days) and the use of large older barrels. The modern approach uses shorter maceration periods (7 to 10 days) and cooler fermentation temperatures (28-30 °C) to preserve fruit flavours and aromas. Towards the end of fermentation, cellars are often heated to kickstart malolactic fermentation and soften the acidity. Modern winemakers tend towards smaller barrels of new oak which imparts vanilla notes but may cover up the characteristic rose notes of Nebbiolo.
In Australia, many early plantings of Nebbiolo went into areas that turned out to be too warm for the variety, though cooler climate sites such as Victoria's King Valley and Mornington Peninsula in Victoria and Western Australia’s Margaret River have similar rainfall, relative humidity and sunshine hours to Piedmont. Bendigo, the Adelaide Hills, the Clare Valley and Mudgee also seem to be suited to the variety.
As far as food matches are concerned, any food you would serve with mushrooms is a fair match for Nebbiolo, as are grilled steak, slow cooked winter casseroles, Bollito misto or Brasato al Barolo (roughly equivalent to Bœuf Bourguignon) and game.